


What Happened to John

by orphan_account



Category: Sherlock (TV), Sherlock Holmes & Related Fandoms, Supernatural
Genre: AU, Demonlock, M/M
Language: English
Status: Completed
Published: 2012-12-25
Updated: 2012-12-25
Packaged: 2017-11-22 10:17:19
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,159
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/608735
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: <blockquote class="userstuff">
              <p>Sherlock didn't notice it at first. Stupid of him really, because he should have been able to tell. He should have known when John had stopped…being John.</p>
            </blockquote>





	What Happened to John

**Author's Note:**

> This is Inasnowfilledwonderland's Sherlock Secret Santa gift. I saw on their tumblr that they were also part of the Supernatural fandom, so I tried a crossover on for size. I hope they like it!

Sherlock didn't notice it at first. Stupid of him really, because he should have been able to tell. He should have known when John had stopped…being John. He'd grown lax, though, in his comfortableness with his flat mate. Sherlock didn't pay as much attention to him, didn't catalog every word and sort every hand gesture. There really wasn't any need to. He believed that if something were to come up that was new, he would see it. It would be different enough to jar him out of his stupor so he could note it down. Unfortunately, things don't work like that.

He saw the small things of course. He saw when John began to take his tea at different times of day, chalking it up to a need for sleep that was better served without the aid of caffeine. He saw the new tie. Silk. He'd even remarked on it, but he'd been shrugged off so he'd shrugged the nagging thought at the back of his mind off as well. John didn't buy silk ties.

Sherlock should have known better.

It was the little things that he'd seen that compiled up until even the violin and five nicotine patches couldn't shake the knowledge that John was not John. Not his John at least. Trouble was, there wasn't anything else he could be.

 

"John--" He started. They were in the sitting room, both in their respective chairs with John tapping away at his laptop far faster than normal. Sixty-one words per minute. Up from twenty-two on a good day. John looked up from his computer expectantly and Sherlock hesitated, hand frozen in place with the page of his book half turned. "Nothing." He said stiffly. "I don't need anything."

"Right." John went back to his typing. Sixty-four words per minute.

"You haven't updated your blog in over a month." Sherlock blurted out. His mouth snapped shut. "I mean--" He tried to start again, backtrack into something that didn't sound as if he'd been keeping a flowchart of John's typing speed, number of blog entries, and number of hits. "Initially I thought it was simply a reaction to Heather declining a third with you, but it's lasted longer than something of that nature would tend towards."

John's fingers stopped their movements and he carefully shut the laptop, putting it to the side so he could fold his hands in his lap. "You've been paying attention." He said, smiling.

"Yes. I have. I always do." Sherlock became aware that he was blinking at a higher rate than normal, indicative of fear or nervousness. It would likely be detrimental if John were to notice as well.

"No, you haven't been." John corrected, lifting one finger as if to stress his point. "At least I hope not. If you have..." He shrugged, "Well then you would be quite the disappointment. Even so, I don't know that you live up to your reputation. It took you long enough."

Sherlock's mouth dropped open when what John said fully processed. It didn't take long. He was telling him what Sherlock already knew to some degree, but it was still a shock to know that John, /his/ John wasn't right any longer. "What--" He swallowed, taking a deep breath, "What are you then?"

"You know." As Sherlock watched, John's eyes blacked out and righted themselves in an instant. It was enough.

"Demon." Sherlock said, voice tight. "You're possessing him." He remembered the last time he'd encountered the supernatural. He had worked to make sure it was his last. He'd failed. Sherlock opened his mouth, lips forming excorsism rights when John grabbed the letter opener sitting on the end table, holding it to his neck.

"Say it and I'll kill him." John said lightly. "I can still use a dead meat suit and it would be a relief to not have to listen to his cries." Sherlock licked his lips and closed his mouth, nodding.

"Alright." Sherlock said carefully. "I won't attempt anything. You have my word, just don't--don't kill him."

"I was right." John smiled, setting the letter opener down but keeping it close at hand. Sherlock raised an eyebrow. "You're not a merciful man, Sherlock Holmes." Sherlock looked down, not meeting the demon's eyes.

"You said you could hear him?"

John laughed, "And he can hear you. See you even. I'm not a merciful man either."

Sherlock leaned forward, forcing himself to look straight at what John should be. "I will find a way." He said clearly, wanting to make sure John would hear him. "Hold on, and I'll get you back. I promise you that, John." He saw John's eyes flash and for a moment he thought-- but that was impossible. He knew the rules of possession.

John sat back as well, pulling his laptop back to him and opening it up. "He loves you, you know. Doesn't want to tell, but there's no hiding it. Frankly, I'm not surprised you haven't noticed." He said casually, not looking at Sherlock while he typed.

Sherlock stood, lips tight. "He knows that I feel the same." He turned on his heel and went to the kitchen, looking out from behind the wall at John while he dialed.

"Winchester? This is Sherlock Holmes." He kept as quiet as possible. "You helped me with the demon possessing my Mother a few years back. I have another problem, and I do hope your skills have improved." He swallowed hard. "I don't want this one to die. Call me back." The phone snapped shut and Sherlock sagged against the wall.

He should have noticed sooner.

 

******************************************************

 

“When was the last time you listened to Dad’s voicemail?” Sam stirred to life from his formerly passed out position in the passenger seat. Dean shrugged, turning the radio down a half bar.

“Week ago maybe? It’s been years. No one calls him anymore. They’re smarter than that.”

“Well give it to me then. I’ll check.” Sam held out his hand and Dean dug the phone out of his pocket with an eye roll. Despite his instance at checking, Sam’s eyebrows still went up at the sight of the symbol with a small 1 blinking above it. “We’ve got one.” He said before putting it on speaker. They both listened, the blood draining out of Dean’s face the further they got.

“This is that one—“ He swallowed hard. “ _London,_ Sammy.”

“A plane. I know.” Sam sighed, scrubbing his face with his hand. “What do you think? We could pass it off.”

Dean shook his head, grip on the steering wheel white knuckled, “No, we can do it. We should do it. That English git Dad went on about? Actually asking for help? This is big, Sam. We’re going to London.” Sam looked at him skeptically for a minute before nodding.

“Alright.” He said, opening the phone back up, “I’ll book us a flight then we’ll call him back. Sherlock Holmes has some explaining to do.” 


End file.
